1. Field of the Invention
The invention relates to a method of producing an inkjet printhead applicable to an image recording apparatus that records information on a recording medium by ejecting ink droplets from nozzles.
2. Description of Related Art
As disclosed in JP-A-2002-105410 (especially FIG. 10) by the present applicant, for instance, there is known a method of producing an inkjet printhead including a cavity unit, a piezoelectric actuator, and a flexible flat cable. The cavity unit has in a front surface thereof a plurality of nozzles arranged in rows, and ink passages for supplying ink as drawn from an ink supply source to the nozzles. The piezoelectric actuator has active portions so as to selectively eject an ink droplet from each nozzle. The flexible flat cable is for supplying electric power to the piezoelectric actuator.
The cavity unit is constructed such that a plurality of flat plates each having an ink-passage pattern are stacked. The ink-passage pattern is for constituting the ink passages, and is mainly constituted by through-holes, but the ink-passage pattern in some of the plates may include recesses also. That is, in the cavity unit, the ink passages are constituted by the ink-passage patterns formed in the plates as stacked. The plates are of various kinds, including a nozzle plate through which the nozzles are formed, a cavity plate in which pressure chambers respectively corresponding to the nozzles are formed in the form of through-holes, and a manifold plate in which common ink chambers for accommodating ink to be distributed to the pressure chambers are formed.
In the production method, a large-sized material sheet is prepared for each kind of a plate constituting the cavity unit. The material sheet includes a predetermined number or a plurality of plate regions that respectively have ink-passage patterns of a same sort for constituting ink passages, a frame encircling the plate regions, and narrow bridges each connecting one of the plate regions and the frame, and all of the plate regions, the frame, and the bridges are integrally formed. The frame has positioning holes formed therethrough in which positioning pins are fitted respectively. A plurality of kinds of material sheets are stacked along the positioning pins that serve as a guide, so as to obtain a laminate of the material sheets. Then, the laminate of the material sheets is segmented by severing all the bridges, into a plurality of individual, discrete laminates of plates.
In the conventional method, however, the frame left after the singulation of the laminate of the material sheets into the individual laminates is useless and discarded, involving some cost.
Further, due to the presence of the frame in the material sheet around the predetermined number of the plate regions, planar dimensions of the material sheet undesirably increase.